1. Field of the Invention
This invention relates to the field of manufacture of artificial fireplace logs, and more specifically to easy lighting artificial fireplace logs.
2. Description of the Prior Art
It is typical of prior art artificial fireplace logs that the time interval from ignition of the log to the time when the log is evenly burning along its length, is on the order of ten to fifteen minutes. Various methods have been used to shorten this time including (1) the use of a flap as discussed below; (2) placing newspaper which has been crumpled or formed into a spindle shape beneath the log and igniting the newspaper; and (3) the use of a groove which contains a "quick lighting" combustible material.
Examples of prior art easy lighting artificial fireplace logs include: L. A. Stevens, U.S. Pat. No. 2,789,890 filed Mar. 8, 1954 issued Apr. 23, 1957; C. P. Ronden, U.S. Pat. No. 3,726,651 filed Dec. 15, 1969 issued Apr. 10, 1973 and Leveskis, U.S. Pat. No. 3,988,121 filed Jan. 9, 1976 issued Oct. 26, 1976.
The artificial fireplace log of Stevens does not show the use of a groove to bring air into contact with a combustible material. Instead, it uses used crank case oil as combustible material and mixes the combustible material with the material used to form the bulk of the log. In contrast, the combustible material of the present invention is not applied to or mixed into the firelog. The combustible material of the device of Stevens is used to promote combustion of the log whereas the combustible material of the device of the present invention is used to achieve easy, rapid, and uniform ignition of the log.
The artificial fireplace log of Ronden shows the use of multiple grooves. However these grooves are used (see Column 4 line 24 to 30) merely to increase the surface area of the log and to provide the log with thin pointed ridges (13), as illustrated in FIG. 3 of Ronden, for easier ignition. The quick lighting combustible material is either sodium nitrate, potassium nitrate, or potassium chlorate which are subject to strict governmental regulations regarding labeling and safety precautions. They are strong oxidizers and are generally hazardous or toxic. They are such strong oxidizers that they do not require an additional external air supply for combustion. They supply their own oxygen for burning. In contrast with the device of the present invention, these oxidizers are mixed together with the material which in prior art fireplace logs is compacted to form the bulk of the log. These oxidizers are used to promote burning of the log, not merely its easy ignition.
The igniter pellet of Leveskis shows the use of a groove. However, the groove is not used as a passageway to supply oxygen, but rather is used merely as a recess into which is placed and retained by compaction a highy flammable and toxic peroxide-cellulosic powder (column 2, lines 11 to 15).
In order to achieve easier ignition Ronden and Leveskis have incorporated substances that are extremely hazardous in manufacturing, transport and end use. The nitrate used in Ronden's process is potentially explosive and the peroxide used in the Leveskis process is not only potentially explosive but highly toxic. Even with igniters incorporated into these two products neither product is designed to be ignited with a wrapper covering the product. Indeed neither product even shows the use of a wrapper. The device of the present invention is capable of being ignited while inside its warapper. However, the use of the wrapper is not required to practice the invention, it being only necessary to supply a means of supporting the combustible material adjacent the groove and spaced from the log. It is not necessary that the log be wrapped.
The prior art also teaches the use of a flap, integrally formed from the material used to wrap the fireplace log. However, prior art flaps were not oriented in any particular direction. All prior art flaps are directed away from the wrapper of the log, but whether the flap was directed away and up or away and down was of no importance. Also included in the prior art is an artificial fire log having a groove formed along its length in which is placed and retained a quantity of a mixture containing diesel fuel. The primary disadvantage of the diesel fuel is its low flash point of between 100.degree. F and 190.degree. F. These artificial fire logs are often shipped and stored in closed containers and subjected to somewhat elevated temperatures which presents an added danger of unintended ignition of the log.
The effectiveness of the flap as it has been conventionally employed is minimal, the crumpled paper is inconvenient, and the use of the diesel fuel (or strong oxidizers such as nitrates and peroxides) in a groove is dangerous.
It is therefore an object of the present invention to produce a firelog which overcomes these disadvantages. The purpose of the easy lighting feature of the present invention is to provide a safe, effective, clean and convenient method for igniting a synthetic firelog. In order to be safe, there must be no hazardous compounds employed. In order to be clean and convenient, the firelog should be able to be ignited without having to open the wrapper and without any form of kindling. In order to be effective, the firelog should become ignited across the full length of the log in a very short time. Of the three patents discussed above, no single patent, nor any combination thereof, can satisfy these requirements.
Even though some of the elements of the present invention are present in each of the three patents discussed, no combination of the three would produce a product that meets the criteria cited above. This is mainly because none of the prior art devices discussed includes a safe or effective combustible material, which is an essential feature of the present invention.
None of the above discussed prior art devices shows the use of a groove to cooperatively admit air (oxygen) to support combustion of an easy lighting combustible material which is placed on the inner surface of the wrapper of the log (rather than mixed into or placed on the log itself) and located directly adjacent to the groove. This specific and unique combination is the heart of this invention. Because the groove admits additional oxygen for combustion, the present invention can employ a less dangerous and more stable combustible material than the prior art devices.